This invention relates generally to rotors, and more specifically to methods and apparatus for balancing a rotor.
Utility grade wind turbines (i.e., wind turbines designed to provide electrical power to a utility grid) can sometimes have rotors of 30 or more meters in diameter. Imbalanced loading in the rotating frame acting on at least some known rotors may occur due to mass imbalance in the blade set, geometrical irregularities in rotor and/or blade mounting, differences in aerodynamic geometry (section, bend, and/or twist) between the blades, and/or differences in pitch angle zero point between the blades. Such imbalanced loads acting on the rotor may be induced to other components of the wind turbine, which may have an impact upon a number of fatigue cycles some components of the wind turbine experience. For example, unbalanced loads acting on the rotor may facilitate fatigue damage of a bedplate that connects a tower of the wind turbine to the ground, may facilitate damage to and/or failure of portions of a nacelle of the wind turbine, and/or may facilitate damage to and/or failure of other components of the wind turbine, such as, but not limited to, main shaft bearings, a yaw system of the wind turbine, and/or the wind turbine tower.